After the big patch last month, the armor of one class was opened to the other class of the same race. A Martial Artist can wear Spiritualist Armor is he wants.
The most important thing for a healer is to stay alive, even if all the players in the party are dead as long as the healer is still alive the battle isn't over yet.
Since most mobs seem to deal physical damage, should I wear the Warrior armor instead of Dragon Clan?